Ceci est une ancienne révision du document !
Welcome back to another quick insight into the very powerful and highly underrated Darktable. We are working with version 2.6, NOT the version that ships with Ubuntu. There are features in 2.6 that you will not find in previous versions. These are the features we are looking at. Darktable 2.6 (or higher) can be obtained via snap/flatpack/ appimage or PPA. (If you are attempting this, you know how to install software on your Ubuntu system). We are working with a noisy picture from the Pentax forums. If you are just joining us, the picture was stolen from here: https://www.pentaxforums.com/gallery/photo-bgirl-grainy-8596/ (Clicking on the photo will enlarge it, for you to save).
Bienvenue pour un autre aperçu rapide du très puissant et largement sous-évalué Darktable. Nous travaillons avec la version 2.6 et PAS celle fournie par Ubuntu. Il y a des fonctionnalités de la 2.6 que vous ne trouverez pas dans les versions précédentes. Ce sont les fonctionnalités que nous allons regarder. Darktable 2.6 (ou au-dessus) peut être obtenu via une appimage snap/flatpack ou un PPA. (si vous essayez ceci, vous savez comment installer les logiciels sur votre système Ubuntu).
Nous travailons avec une image bruitée issue des forums Pentax. Si vous nous rejoignez maintenant, l'image a été volée ici : https://www.pentaxforums.com/gallery/photo-bgirl-grainy-8596/ (en cliquant sur l'image, elle est agrandie, et vous pouvez l'enregistrer).
Working with one picture keeps everyone on the same page, however you are very welcome to use your own noisy picture! I hope everyone has been experimenting with the various options to correct the noise. This is the only way to learn, and practice makes perfect. Darktable 2.6 sports two new features called ‘filmic’ and ‘retouch’. See: https://www.darktable.org/2018/12/darktable-26/ - You can find them in “more modules” on the right. Filmic does just what it says on the box, it mimics shooting on film. (We will get to it soon). Retouch, on the other hand, makes spot removal look like a freeware toy. I don't even know why they kept spot removal in there. Load up retouch now.
En travaillant sur une image chacun est au même niveau, mais vous pouvez travailler, si vous le voulez, avec votre propre image bruitée !
J'espère que chacun a essayé les différentes options de correction du bruit. C'est la seule façon d'apprendre et la pratique rend parfait.
Darktable 2.6 apporte des nouvelles fonctionnalités appelées « filmique » et « retouche ». Voir : https://www.darktable.org/2018/12/darktable-26/ - Vous pouvez les trouver dans « plus de modules » sur la droite. Filmique fait ce qui est dit sur la boîte, il mime le tournage d'un film. (Nous y reviendrons bientôt). Retouche, d'un autre côté, fait ressembler la suppression ponctuelle à un jeu gratuit. Je ne sais même pas pourquoi ils gardent la suppression ponctuelle ici. Chargez retouche maintenant.
You may wonder about these blocks. They are scales. Feel free to mouse over them to read the tool tips. Adding scales, is like adding layers of granularity. If you add two, you will have a rough / coarse and a smooth / fine layer. Add two more and you break each of those into the same. Get the idea? You can think of it like music scales. We will play later, for now, I would just like to give you an overview and brief explanation. If you look below the blocks, you will see retouch tools, with shapes in the top row and algorithms in the bottom. Mouse over each to identify them. It will tell you what they are, but not what they do. This is where your friendly Full Circle Magazine steps in and explains what each one does. (Just not right now, keep reading). I like taking pictures at air shows, but I often find that at maximum zoom, I see spots or dust or lint when I review my pictures afterwards. Spot removal is basically copy and paste, and you can usually see it. (Why is the sky not uniformly blue?). The new heal tool is that plus blending into the surrounding pixels. So you will probably love it too.
Ces blocs vous posent peut-être des questions. Ce sont des échelles. n'hésitez pas à passer la souris dessus pour lires les info-bulles. Ajouter des échelles, c'est comme ajouter des couches de granularité. Si vous en ajoutez deux, vous aurez une couche rêche et grossière et une douce et agréable. Ajoutez-en deux autres et vous diviserez chacune d'elle de la même façon. Vous comprenez l'idée ? Vous pouvez penser à ceci omme à des portées musicales. Nous jouerons avec plus tard ; pour l'instant, je voudrais juste vous donner un aperçu et une courte explication. S vous regardez sous les blocs, vous verrez les outils de retouche, avec les formes sur la ligne du haut et les algorithmes sur celle du bas. Passez la souris au-dessus pour les identifier. Elles vous seront présnetées, mais sans vous dire ce qu'elles font. C'est là qu'intervient votre amical Full Circle Magazine qui explique ce fait chacun. (Mais pas tout de suite, continuez à lire).
J'aime prendre des photos dans les meetings aériens, mais je trouve souvent, qu'au zoom maximum, je vois des points ou de la poussière ou de la peluche quend je revois mes images après coup. La suppression des points est comme un copier/coller et vous pouvez en général la voir. (Pourquoi le cile n'est-il pas uniformément bleu ?) Le nouvel outil de cicatrisation, c'est ça plus un mélange dans les pixels avoisinants. Aussi, vous l'aimerez probablement.
Before we go using all these tools, or perhaps you have already – I am going to bring your attention back to the scales. You will notice a red box inside the very first rectangle. This is where you are currently editing. Moving up the scale to the right is a lot like ‘onion skinning’ - adding another “layer” through which the picture appears more grainy. To get a feel for this, add five scales (by dragging the bottom triangle right) and look just below the blocks, the very first icon ‘display wavelet scale’, click on it. Now click on the first block, then the second, and so on, to see the image change as your red block moves within the rectangles, which has now turned grey. You can go past your level of scale (past the white rectangle), but this is pointless. Whilst clicking through your scales again, look at the histogram in the top right. See how the angle widens between the first and fifth block. You will also have noticed a new slider with three triangles on it where it says, ‘preview single scale’. You are welcome to play with those, and to the right of that you will see what looks like a trident. This is the ‘auto levels’, which will adjust your histogram to the ‘best’ settings, defined by the algorithm. Only on that one layer you are on.
Do you understand the power at your fingertips yet? Yes, dear reader, this is power editing! Okay I hope you have the picture of the girl loaded and ready to be edited. Centre it on her nose and look for the two freckles. I am going to treat the freckles as blemishes, though they are not, just so you can see this in action. Add eight scales. At scale four you should just start to see the freckles. Now we get to the shapes. The first one, that looks like a pencil, is add brush. We will skip it for now. The second is the circle, click on it and bring your cursor on to the face. You will see something like this:
Now scroll your mouse wheel forward to tighten the circle and then hold down shift and repeat the action to tighten the feathering. Click on the ‘blemish’, then drag nearby in any direction that looks like it could be a good match. Repeat for both. You will now see a green line inside the scale you are editing in. This indicates you have done something here. Now move another layer up and repeat. You do not have to drag to the same area, which is the beauty of this. In fact if you drag to other areas, you can make it look more natural. When you are done, click back on the very first scale and be amazed at your elite editing skills. The kind Vogue magazine pays someone six figures for!
I will leave you here to play, and, in the next issue, we will continue with more of the tools. Happy editing. If you have any queries, you can contact me on the FCM Telegram group: https://t.me/joinchat/BqDEzj7o5FQkPzHjvccQnw